XAVCS trascoded to MXF issue "EXCEPTION DISK FILE NOT FOUND"

I'm trying to solve a weird issue in these days without any progress so i'd be happy to have some help. I explain my situation.

I have a Sony a6300 and I think everybody knows that this is already a problem for MC unfortunately. Anyways, everytime I shoot something with it, i have to trascode my footage throught Da Vinci resolve from XAVS to MXF OP-Atom with relative AAF. Then, I copy my new MXF footage and I paste it in my Avid MediaFiles folder, then I open my MC and I import my AAF, in this way it will find all my media file in my Avid Media File folder. I have always used this workflow and it has always worked until yesterday. Now, when I import my AAF a MC error dialog box appers and says "EXCEPTION DISK FILE NOT FOUND, AN ERROR OCCURRED VALIDATING THE MEDIA DIRECTORY: Volumes/MEDIA/Avid MediaFile/MXF/4. (My HD path)

Now, you have to know that I used an external hard disk to do that, so at first I thought there was something wrong with it. 1) First i deleted the media database .pmr and .mdb so that MC could re create them but the problem persist.

2) Then I erased the hard drive, I tried again but the problem persit.

3) I made MC create a new Avid MediaFiles folder importing a move file and he trascoted as usual on the hard drive (so the problem can't be the hard disk)

4)I changhed the hard drive with another one but the problem persist.

I really can't understand why it doesn't works now and two week ago it did. I made the same process! The weird thing is that I try this process on two different PC and i have always the same problem. ( Even with difference versions of MC)

At the end i just tried to put everything on the internal hard disk and with a lot of pleasure it worked for something like a day. The next day MC gave me the identical problem of the day before. I really don't know what i have to do.